System for controlling a tissue-stapling operation

ABSTRACT

An endoscopic stapler is disclosed. The stapler includes a staple member and an anvil member. The staple member may include a staple housing and the staple holder may include one or more staples. The anvil member may be spaced apart from the staple member and may configured to relatively move towards one another. A controller may be fluidly coupled to the staple member through a plurality of conduits. The controller may be configured to (a) direct a pressurized fluid to the staple member through a first conduit of the plurality of conduits to relatively move the staple member and the anvil member towards one another, and (b) direct the pressurize fluid through a second conduit of the plurality of conduits to eject one or more staples from the staple holder.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/801,344 filed Mar. 15, 2013, which is incorporated by reference inits entirety herein.

FIELD OF THE INVENTION

The present invention relates to a system and method for controlling theoperation of a tissue-stapling device, such as controlling the operationof a remote, intra-oral stapling device by controlling the amount andpressure of fluid to the device.

BACKGROUND

Tissue plication devices for capturing and stapling a tissue fold byremote access, e.g., for forming stapled tissue folds within the cavityof the stomach by means of intraoral access, are known. One suchintraoral device, which functions to draw a tissue fold into anexpandable tissue vacuum chamber, and staple the fold with an annulararray of staples, is described in U.S. Pat. Nos. 8,020,741, 7,922,062,7,913,892, 7,909,223, 7,909,222, 7,909,219, 7,721,932 and 7,708,181, allof which are incorporated herein by reference.

It would be desirable, in the operation of a tissue-plication device ofthe type described above, to be able to control tissue acquisition,compression, and stapling under conditions that optimize operation ofthe device, produce a stapled plication under reproducible conditions,and also allow for automatic operation or user intervention to initiate,pause and/or abort certain functions.

SUMMARY OF THE INVENTION

In one aspect, an endoscopic stapler is disclosed. The stapler mayinclude a staple member and a staple holder. The staple holder mayinclude one or more staples. The stapler holder may also include ananvil member spaced apart from the staple member, wherein the staplemember and the anvil member are configured to relatively move towardsone another. The staple holder may also include a controller fluidlycoupled to the staple member through a plurality of conduits. Thecontroller may be configured to (a) direct a pressurized fluid to thestaple member through a first conduit of the plurality of conduits torelatively move the staple member and the anvil member towards oneanother, and (b) direct the pressurize fluid through a second conduit ofthe plurality of conduits to eject one or more staples from the stapleholder.

Additionally or alternatively, in some aspects, the staple member mayinclude a hydraulic chamber fluidly coupled to the controller throughthe plurality of conduits, the hydraulic chamber may include a firstpiston and a second piston therein, wherein the first piston may beconfigured to relatively move the staple member and the anvil membertowards one another, and the second piston may be configured to ejectone or more staples from the staple holder; the second piston may bepositioned within the first piston; directing pressurized fluid throughthe first conduit may jointly move the first piston and the secondpiston from a first position to a second position, and directingpressurized fluid through the second conduit may move the second pistonrelative to the first piston from the second position to a thirdposition away from the first position; the first conduit may be coupledto a first fluid source containing a predetermined quantity of fluid andthe second conduit may be coupled to a second fluid source containing apredetermined quantity of fluid; the stapler may further include a firstswitch, the activation of which initiates the supply of pressurizedfluid from the first fluid source through the first conduit; the staplermay further include a first sensor adapted to detect a pressure appliedto the staple member in response to pressurized fluid in the firstconduit; the stapler may further include a second switch, the activationof which initiates the supply of pressurized fluid through the secondconduit; the second switch may be automatically activated when the firstsensor indicates that a preselected pressure has been reached; andrelative movement of the staple member and the anvil member towards oneanother may include (i) the staple member moving towards the anvilmember, and (ii) the anvil member moving towards the staple member.

In another aspect, an endoscopic stapler is disclosed. The stapler mayinclude a staple member including a hydraulic chamber with a firstpiston and a second piston positioned therein, and a staple holderincluding one or more staples positioned therein. The stapler may alsoinclude an anvil member spaced apart from the staple member. The staplemember and the anvil member may be configured to relatively move towardsone another. The stapler may further include a controller fluidlycoupled to the hydraulic chamber. The controller may be configured to(a) jointly move the first piston and the second piston from a firstposition to a second position to relatively move the staple member andthe anvil member towards one another, and (b) move the second pistonrelative to the first piston from the second position to a thirdposition to eject one or more staples from the staple holder.

Alternatively or additionally, the controller may be fluidly coupled tothe hydraulic chamber through a first conduit and a second conduit,wherein directing pressurized fluid through the first conduit may beeffective to jointly move the first piston and the second piston fromthe first position to the second position, and directing pressurizedfluid through the second conduit may be effective to move the secondpiston from the second position to the third position; the stapler mayfurther include a first switch, the activation of which may initiate thesupply of pressurized fluid through the first conduit, a first sensorconfigured to detect a pressure applied to the staple member in responseto pressurized fluid in the first conduit, and a second switch, theactivation of which initiates the supply of pressurized fluid throughthe second conduit, wherein the second switch may be automaticallyactivated when the first sensor indicates that a preselected pressurehas been reached; the controller may be coupled to a first fluid sourceand a second fluid source, wherein the controller may be configured to(i) direct fluid from the first fluid source to the hydraulic chamber tojointly move the first piston and the second piston from the firstposition to the second position, and (ii) direct fluid from the secondfluid source to the hydraulic chamber to move the second piston from thesecond position to the third position; and relative movement of thestaple member and the anvil member towards one another may include (i)the staple member moving towards the anvil member, and (ii) the anvilmember moving towards the staple member.

In another aspect, a method of operating an endoscopic stapler includinga staple member with one or more staples and an anvil member isdisclosed. The method may include positioning the stapler within apatient, actuating a controller a first time, and actuating thecontroller a second time. Actuating the controller a first time maydirect a pressurized fluid to the staple member through a first conduitto relatively move the staple member and the anvil member towards oneanother, and actuating the controller the second time may direct apressurized fluid to the staple member through a second conduit to ejectone or more staples from the staple member.

Alternatively or additionally, relatively moving the staple member andthe anvil member towards one another may include (i) moving the staplemember towards the anvil member, and (ii) moving the anvil membertowards the staple member; the staple member may include a hydraulicchamber with a first piston and a second piston positioned therein, andactuating the controller a first time may include jointly moving thefirst piston and the second piston from a first position to a secondposition to relatively move the staple member and the anvil membertowards one another; and actuating the controller a second time mayinclude moving the second piston relative to the first piston from thesecond position to a third position to eject one or more staples fromthe staple member; the method may further include positioning tissuebetween the staple member and the anvil member before the step ofactuating the controller a second time.

The invention includes, in one embodiment, an external controller foruse in controlling the operation of a surgical staple device thatincludes (i) a stapler having staple and anvil members movable towardand away from one another to a capture position, for capturing at leastone tissue layer therebetween, and first and second pistons controllingthe movement of the staple and anvil members toward one another, and forejecting one or more staples from the staple member, respectively, and(ii) a shaft having first and second fluid-carrying conduits connectableto the controller for communicating the controller with the first andsecond pistons in the device, respectively. The controller includes:

a. first and second fluid sources adapted to supplying pressurized fluidfrom the first and second fluid-carrying conduits in the shaft to thefirst and second pistons, respectively;

b. a first switch whose activation initiates the supply of pressurizedfluid from the first fluid source to the first piston, to move thestaple and anvil members toward one another;

c. a first sensor for sensing the pressure applied to the staple memberat the capture position, in response to fluid supplied to the firstpiston; and

d. a second switch whose activation requires the sensing of apreselected pressure applied to the staple member at the captureposition, and which initiates the supply of pressurized fluid from thesecond fluid source to the second piston, to drive a staple from thestaple member through tissue captured between the staple and anvilmembers.

In various aspects, the first and second fluid sources may beliquid-carrying syringes; the second switch may be automaticallyactivated to initiate supply of pressurized fluid from the second fluidsource to the second piston after the sensor indicates that suchpreselected pressure has been reached; where the first fluid source is aliquid-carrying syringe, the first sensor measures the liquid pressureapplied by the first source; for use in controlling the operation of asurgical stapling device in which the staple and anvil members aremovable toward and away from one another along an axis, for acquiring atissue fold within an expandable vacuum tissue-acquisition chamberdefined between the staple and anvil members, the first and second fluidsources are liquid-carrying syringes and the controller include a secondsensor for indicating the volume of fluid supplied from the first sourceto the first piston, as an indicator of the relative positions of thestaple and anvil members, as they are moved toward one another. Thecontroller may include a stepper motor that drives fluid from the firstsyringe by motor rotation, and the second sensor may function todetermine the total rotation of the motor, as a measure of the volume offluid supplied by the first fluid source. The first sensor may measurethe liquid pressure produced by the first source.

In another aspect, the invention includes an external controller for usein controlling the operation of a surgical-staple device that includes astaple having staple and anvil members movable toward and away from one,from an open position to a tissue-acquisition position and from thetissue-acquisition position to a capture position, and first and secondpistons controlling the movement of the staple and anvil members towardone another, and for ejection one or more staples from the staplemember, respectively, and a shaft having first and second fluid-carryingconduits connectable to the controller for communicating the controllerwith the first and second pistons in the device, respectively. Thecontroller comprises:

a. first and second liquid-carrying syringes adapted to supplypressurized liquid from the first and second syringes conduits in theshaft to the first and second pistons, respectively,

b. a first switch whose activation initiates the supply of pressurizedliquid from the first syringe to the first piston, to move the stapleand anvil members from their open to tissue-acquisition position,

c. a first sensor for sensing when the staple and anvil members are attheir tissue-acquisition position, based on the volume of liquidsupplied to the first piston, at which tissue is acquired between thetwo members,

d. a second switch whose activation initiates the supply of pressurizedliquid from the first syringe to the first piston, to move the stapleand anvil members from their tissue-acquisition position to theircapture position,

e. a second sensor for sensing the pressure applied to the staple memberat the capture position, in response to fluid supplied to the firstpiston, and

f. a third switch whose activation requires the sensing of a preselectedpressure applied to the staple member at the capture position, and whichinitiates the supply of pressurized fluid from the second fluid sourceto the second piston, to drive a staple from the staple member throughtissue captured between the staple and anvil members.

The controller may include a stepper motor that drives fluid from thefirst syringe by motor rotation, and the first sensor may function todetermine the total rotation of the motor, as a measure of the volume offluid supplied by the first fluid source. The controller may function toautomatically acquire a tissue fold between the staple and anvil memberswhen the members are in their tissue-acquisition position. For use witha stapler device that includes a vacuum tissue-acquisition chamberdefined between the staple and anvil members, the controller may furtherincludes a fourth switch for initiating the supply of vacuum to thechamber, to acquire a tissue fold therein. The fourth switch may beautomatically activated to initiate supply of pressurized fluid from thesecond fluid source to the second piston after the first sensorindicates that the staple and anvil members are in theirtissue-acquisition position.

In still another aspect, the invention includes a system for capturingand stapling one or more layers of tissue. The system includes a staplerdevice having staple and anvil members that can be moved together, tocapture and staple one or more tissue layers between the two members, aliquid-carrying syringe for supplying pressurized liquid to a firstpiston in the device, whose activation causes the staple and anvilmembers in the device to move to a tissue-capture position at which theone or more tissue layers are captured between the staple and anvilmembers, a fluid line connecting the syringe to the first piston, afluid release mechanism on the device between the line and piston, toallow air in the syringe and line to be removed before operation of thesystem, a sensor for sensing the pressure applied to the syringe, and aswitch which prevents activation of the syringe during operation until apreselected pressure is sensed by the sensor. The fluid releasemechanism may be, for example, a bleed screw.

These and other objects and features of the invention will become morefully apparent when the following detailed description of the inventionis read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic illustration of a human stomach and a portion ofthe small intestine, as known in the prior art;

FIG. 1B is a cross-sectional perspective view of a portion of a stomachwall, illustrating the layers of tissue forming the wall, also as knownin the prior art;

FIG. 2 illustrates a tissue-plication device constructed in accordancewith an embodiment of the invention, also showing tools for intra-orallyplacing the device in a patient's s stomach;

FIG. 3 is a perspective view of a tissue-plication device controllerconstructed according to an embodiment of the invention;

FIGS. 4A-4C are top plan views of the tissue-capture and stapling headin the plication device, showing the head in its low-profile condition(4A), during travel of the staple and anvil members toward atissue-acquisition condition (48), and the head in its tissue-capturecondition (4C);

FIG. 5 is a perspective view of the head in the above plication device,showing a bleed screw for removing gas from the pressurized liquid linessupplying the pistons in the head;

FIGS. 6A-6D are a series of schematic representations of the hydraulicchamber and pistons in an exemplary stapler used in conjunction with thecontroller of the invention;

FIG. 7 is a perspective view of the controller in the invention, showingfirst and second syringes and pressures sensors in the controller;

FIG. 8 is an enlarged view of a pusher unit in the controller;

FIG. 9 is a diagram of operations carried out by the controller and userduring operation of the controller in a tissue-stapling operation; and

FIG. 10 is a flow diagram showing sensor and activation eventsassociated with the logic circuit in the controller.

DETAILED DESCRIPTION OF THE INVENTION

The present application describes a system and controller forcontrolling the operation of tissue-stapling device, such as a devicefor forming tissue plications within the stomach of a patient byintra-oral access. As will be detailed below, the tissue-stapling deviceincludes a tissue-acquisition and stapling head and a shaft to which thehead is attached at the shaft's distal end. The system of the inventionincludes the combination of controller and device, where the controllercontrols is connected to the proximal end of the shaft, and controls thevarious operations of the device as will be seen.

An anatomical view of a human stomach S and associated features is shownin FIG. 1 A. The esophagus E delivers food from the mouth to theproximal portion of the stomach S. The z-line or gastro-esophagealjunction Z is the irregularly-shaped border between the thin tissue ofthe esophagus and the thicker tissue of the stomach wall. Thegastro-esophageal junction region G is the region encompassing thedistal portion of the esophagus E, the z-line, and the proximal portionof the stomach S. Stomach S includes a fundus F at its proximal end andan antrum A at its distal end. Antrum A feeds into the pylorus P whichattaches to the duodenum D, the proximal region of the small intestine.Within the pylorus P is a sphincter that prevents backflow of food fromthe duodenum D into the stomach. The middle region of the smallintestine, positioned distally of the duodenum D, is the jejunum J.

A. Stapler System

FIG. 1B illustrates the tissue layers forming the stomach wall. Theoutermost layer is the serosal layer or “serosa” S and the innermostlayer, lining the stomach interior, is the mucosal layer or “mucosa”MUC. The submucosa SM and the multi-layer muscularis M lie between themucosa and the serosa.

In the disclosed invention, a stapler device having a stapler carried atthe distal end of a shaft is introduced into the stomach intra-orally,via the esophagus. Typically the device is equipped with an endoscopethat allows the physician to view the interior region of the stomach,and guiding structure by which the device can be positioned at a desiredtarget location within the stomach, i.e., the region at which the devicewill form a tissue fold. When the stapler is placed against a tissueregion, and vacuum is applied, a portion of the interior stomach wall isdrawn inwardly into the device, forming a two-layer fold or plicationthat brings sections of serosal tissue on the exterior of the stomachinto contact with one another. After bringing opposed sections of tissuetogether in a compressed state, the stapler is activated to deliver oneor more fasteners, e.g., one or more staples, that will hold the tissuelayers together until at least such time as serosal bonds form betweenthem. Each of these steps may be performed wholly from the inside of thestomach and thus can eliminate the need for any surgical or laparoscopicintervention. After one or more plications is formed, medical devices(including, but not limited to any of the types listed above) may becoupled to the plication(s) for retention within the stomach.

The stapler device may include, in addition to a fastener for fasteningtissue folds formed in the device, a blade that forms a hole or cut in aplication using the fastener-applying device. This hole or cut might beformed so that a portion of a medical implant may be passed through orlinked to the hole/cut, or it may be formed so as to provoke a healingresponse that will contribute to the strength of the resulting tissuebond.

FIG. 2 illustrates one embodiment of a stapler device 20 which includesa stapler 22, for stapling one or more tissue layers, for example, forcapturing and stapling a two-layer tissue fold or plication, and aflexible shaft 24 which carries the stapler at its distal end. Thedevice is connected, at a distal-end handle portion 26 of the shaft, toa vacuum source 28 and to a controller 170, shown in perspective view inFIG. 3, for controlling various tissue acquisition, tissue compression,and tissue stapling operations in a manner to be described. As shown inFIG. 3, and described in detail below, the controller includes a pair offluid-source assemblies, indicated at 174, 176 in FIG. 3, for supplyingpressurized fluid, e.g., water, to first and second pistons in thestapler, through a pair of high-pressure lines (not seen) carried in theshaft. The controller fluid lines are connected to the shaft throughfluid connections at the shaft handle portion, such as indicated at 32.

The vacuum source may be the “house vacuum” or vacuum pump. Also shownis an reservoir tank 34 connecting the vacuum source to the handle, forcontrolling the rate at which vacuum is applied to thetissue-acquisition device. Although not shown here, the vacuum source isconnected to controller 30, which includes a switch (not shown) forconnecting the vacuum source, e.g., pump, to the stapler, through aseparate fluid line extending through the shaft.

An endoscope 36 in the system is insertable through a lumen in theshaft, and permits visualization of the plication procedure. The systemmay optionally include an overtube, such an endoscopic guide tube 38,having a lumen for receiving the shaft and attached device 22.

B. Exemplary Stapler

An exemplary stapler 22 for use with the controller of the invention isdesigned for acquiring a two-layer tissue fold, capturing the foldbetween staple and anvil members, and stapling the fold to form a tissueplication. It will be appreciated from below, however, that thecontroller of the invention can be used to control a variety of tissuestaplers, including those designed for repair a single tissue layer, andthose in which the staple and anvil members pivot toward one another, ina clamp-type motion, rather than move reciprocally toward and away fromone another along an axis, as does stapler 22.

For purposes of description in this section, stapler 22 will bedescribed with respect to its mechanical elements and to the operationof those elements illustrated in FIGS. 4A-4C and FIG. 5. It will beunderstood from below that the stapler illustrated in these figures alsoincludes a flexible elastomeric sleeve (not shown) that covers themechanical elements of the device, and which forms a vacuum chamber fortissue-acquisition between the staple and anvil members.

Stapler 22 is designed to have a minimum profile, shown in FIG. 4A,during insertion to the plication site; and is designed to expand to theprogressively larger profiles seen in FIGS. 4B and 4C during atissue-acquisition operation. Considering now the mechanical elements ofstapler 22, a first or proximal or staple member 50 includes a housing52 and a staple holder 54 that moves within the housing along an axis 56extending in a horizontal direction in the figures. The extent of travelof the staple holder within the housing is limited by a pair of pins 57that travel within slots 59 formed in the housing, as can be appreciatedfrom the positions of the pins in FIGS. 4A and 4C. A second or distal oranvil member 58 includes a housing 60 and an anvil 62 that moves withits associated housing also along axis 56. The staple and anvil membersare connected by a pair of arm assemblies 64 for movement toward andaway from one another, along axis 56, between the low-profile conditionshown in FIG. 4A and the fully expanded condition shown in FIG. 4C. Eacharm assembly has proximal and distal arms 66, 68, respectively, that arepivotally joined to one another at their confronting ends, formingelbows in the assemblies, and are pivotally joined at their oppositeends to the associated member 50, 58, respectively.

A pair of spreader arms 70 are anchored within housing 52 through pins57, and pivotally attached to associated assembly arms 66 at theopposite ends of the spreader arms. As can be appreciated from thefigures, movement of staple holder 54 within its housing to the right inthe figures, with corresponding travel of pins 57 within slots 59, actsto push spreader arms 70 outwardly, causing arms 66, 68 to spreadoutwardly and draw the two housings toward one another. At the sametime, outward movement of arms 68 acts to move anvil 62 within itshousing, toward the left in the figures, through a scissor-arm mechanism72 connecting the distal ends of arms 68 to the anvil.

Stapler 22 also has flexible lifter arms 78 whose opposite ends arepivotally joined to the proximal and distal members, as seen in FIG. 5.The lifter arm functions to expand the cross-sectional area of thechamber in conjunction with the expansion of the two arm assemblesduring operation of the device, as can be appreciated from FIG. 5. In anexemplary embodiment, a vacuum chamber 46 in the stapler, defined by thearm assemblies and spreader arm and the confronting faces of the stapleand anvil members, has a cross-sectional area of about 0.7-0.8 cm2 inthe low-profile condition shown in FIG. 4A, and a maximumcross-sectional area of 7-8 cm2 in the fully expanded condition shown inFIG. 4C.

Also shown in FIG. 5 is a bleed screw 77 which allows pressurized fluidsupplied to the stapler through the fluid conduits in the shaft to bedrawn off, to ensure that the fluid pathway from controller 170 to thestapler is substantially free of air, as described below. The bleedscrew is also referred to herein as a fluid-release mechanism betweenthe fluid line and stapler pistons, to allow air or other gas in thesyringe and line to be removed before operation of the system. Otherrelease mechanism could include a spring-bias release button, forexample.

Stapler movement is under hydraulic control, and includes a first pistonfor moving the staple and anvil relatively toward and away from another,from the open position or condition seen in FIG. 4C, to atissue-acquisition position or condition at which tissue is drawn intotissue chamber 46 between the confronting faces of the staple and anvilmembers, such as shown in FIG. 48, to a closed, capture position orcondition, shown in FIG. 4C. The latter position is defined in exemplarystapler 22 by the farthest extent of travel allowed by the movement ofpins 57 within slots 59, as described above, and places the staple andanvil members at a position with a gap d (FIG. 4C) between theirconfronting faces. That is, the stapler operates to capture a tissuefold and compress it to a total thickness d. Actual stapling, whichoccurs when a tissue fold is captured between the staple and anvilmembers at the capture position, is effected by a second piston thatdrives one or more staples out of the staple holder, through thecaptures tissue fold, and against the anvil, where the staple ends arebent against the “back” side of the fold, to form the tissue plication.As will be seen below, one object of the present invention is to controlthe operation of the two pistons in a way that the staple and anvilmembers are held in a sufficiently rigid configuration to produce atight stapling of the tissue.

FIGS. 6A and 68 schematically show the fluid flow in the hydraulicchamber 66 of the staple housing 28 during both compression and staplingstages of actuation. Referring to FIG. 11A, compression piston 106 isdisposed within hydraulic chamber 66. Disk 68 is positioned in contactwith or slightly distal to piston 106. Compression piston 106 isgenerally cup-shaped, having a rear wall 108 and a side wall 110enclosing an interior 111. O-ring seals 112 are spaced-apart on aproximal portion of the side wall 110. Channels 166 are formed throughthe side wall 110, between the o-ring seals 112.

A second piston, referred to as the staple piston 168, is positioned inthe interior 111 of compression piston 106, against the rear wall 108.Although not shown in FIGS. 6A-6D, cutting element 86, with the staplepusher 76 thereon, is positioned in contact with or slightly distal tothe staple piston 168. An o-ring seal 118 surrounds a portion of thestaple piston 168 that is distal to the channels 166 in the compressionpiston.

A first fluid channel 120 extends from fluid port 50 a in the staplerhousing 28 to a proximal section of the hydraulic chamber 66. A secondfluid channel 122 extends from fluid port 50 b in the stapler housing toa more distal section of the hydraulic chamber 66. Fluid flow from port50 a and fluid channel 120 against the compression piston cylinder isshown in FIG. 6A. Fluid pressure within the hydraulic chamber 66advances the compression piston 106, with the stapler piston 168 withinin it, in a distal direction. FIG. 6B shows the compression piston 106approaching the end of its travel. Once the compression piston reachesthe end of its travel as shown in FIG. 6C, channel 166 in thecompression piston 106 aligns with channel 122 in the housing, allowingfluid introduced through fluid port 50 b to enter the interior of thecompression piston 106 via channel 122. The fluid entering the interiorof the compression piston drives the staple piston distally as shown inFIG. 6D.

Actuation of the device is by compressed fluid supplied to a pistonwithin housing 50 (not shown). This causes stapler 54 to move to theright in the figures relative to housing 50, as seen in FIGS. 4B and 4C,in turn causing the two spreader arms in the device to pivot away fromone another, and forcing the two arm assemblies toward their expandedpositions shown sequentially in FIGS. 4B and 4C. That is, actuation ofthe driving piston in the device causes the following sequence ofevents: (1) movement of the stapler within its housing along axis 56toward the right in the figures, indicated by arrow A1 in FIG. 4B, (2)movement of the spreader arms and pivotally attached arm assembliesoutwardly, away from axis 56, (3) movement of the two housings towardone another along axis 56, indicated by arrow A2 in FIG. 4B, (4)expansion of the spreader arm, and (5) movement of the anvil within itshousing to the left along axis 56, indicated by arrow A3 in FIG. 4B.When the device has executed its full extent of travel, that is, whenpins 57 reach their stop positions within slots 59, the stapler andanvil are positioned at a tissue-capture condition, seen in FIG. 4C, atwhich the confronting faces of the stapler and anvil, indicated at 74,76, respectively, are separated by a gap d. In an exemplary embodiment,distanced is selected between 0.06-0.07 inches (e.g. for use withstaples having legs of 5.5 mm length) or 0.105 to 0.115 inches for 6.5mm leg length staples. Application of additional pressure into thehydraulic circuit will not compress the tissue any further.

A vacuum applied to the device at the same time or shortly after themechanical elements are being driven toward their fully expandedcondition, acts to draw tissue into the chamber. As it is being drawnin, the tissue fold expands outwardly, tending to fill the expandingcross section of the chamber, until the tissue chamber is fully expandedand the tissue fold is captured between the confronting faces of thestapler and anvil. Details of the device just described, and its mode oroperation, are given in co-owned U.S. Pat. Nos. 8,020,741, 7,922,062,7,913,892, 7,909,233, 7,909,222, and 7,909,219, all of which areincorporated herein in their entirety. In particular, these patentsdescribe in detail how staples are and ejected through a tissue.

With continued reference to FIGS. 4A-4C, stapler 22 includes aflexible-membrane covering not shown which covers the mechanical,tissue-capture elements of the device that are described below. Thecovering and certain mechanical elements that it covers form a vacuumchamber 46 in the device. The sleeve may be formed, for example, ofsilicone or other elastic, biocompatible material, and at least acentral portion of the sleeve is sufficiently transparent to allow theuser to view the interior of the tissue chamber during operation, toconfirm (via endoscopic observation) that an appropriate volume oftissue has been acquired.

C. Controller

FIG. 7 shows the controller 170 of the invention in perspective view.The controller is housed in a case 175 having an upper lid 172.Fluid-source assemblies 174, 176 in the controller supply fluid underpressure to the first and second pistons, respectively, in stapler 22,to control the operation of the stapler in accordance with theinvention.

Fluid-source assembly 176, which is representative, includes a syringe178 supported on case 175, and projecting outwardly therefrom. Thesyringe terminates at a distal fitting 180 connectable and to a socket,such as indicated at 32 on the handle portion of shaft 24 (FIG. 2), toform a fluid-tight connection with the stapler device. For mounting, theproximal flanged end of the syringe is snugly received in a U-shapedslot 184 formed in the side of case 175. A typical syringe is astainless steel syringe having an 8 cc volume. Fluid, e.g., water, isexpelled from the syringe under pressure by movement of a syringeplunger 186 in a left-to-right direction in the figure.

With reference to FIGS. 7 and 8, plunger 186 is attached at its proximalflanged end in a U-shaped slot 188 formed on the side of a pusher unit190, mounting the plunger for movement along the long axis of thesyringe. A fixed mounting bar 192 is slid ably received in an opening194 extending through the lower portion of the unit in the FIG. 7. Alead screw 196 is threadedly received in a threaded opening 198extending through an upper portion of the unit in the figure.

Lead screw 196 is driven for rotational motion, in a direction thatadvances the pusher unit in a left-to-right direction in the FIG. 7 by astepper motor (not shown) mounted in the controller to the left of thelead screw in FIG. 7. The stepper motor may be for example, aconventional 2-phase bipolar stepper motor with 1.8 degree step. Whenthe stepper motor is activated, by one or more switches described below,the controller supplies a suitable current, e.g., 2.5 amps, to the motorthrough a clock circuit which records the time that the motor is on,i.e., activated. Rotation of the lead screw advances unit 190, forcingplunger 186 into the syringe and expelling syringe fluid, e.g., water,from the syringe into the stapler unit. The total volume of fluidexpelled from the plunger can thus be measured by the total clock timefor stepper-motor activation. The clock in the circuitry is alsoreferred to herein as a sensor for sensing total volume expelled by thefluid source, i.e., syringe. Alternatively, syringe volume expelledcould be monitored by any of a variety of optical, electrical, ormagnetic position sensors capable of detecting the position of theplunger during plunger movement.

Unit 190 also includes a load-cell type pressure sensor 194 (FIG. 8) forsensing the force applied by unit 190 to the flanged end of plunger 186.The term “pressure sensor” is used interchangeably with “force sensor”herein since pressure and force are related by the syringe borecross-sectional area. Sensor 194 is mounted on unit 190, within slot 188for contacting the plunger flange received in the slot. The sensor maybe, for example, a strain gauge or a capacitive sensor that measuresmovement of a diaphragm in response to increased physical pressure onthe sensor. The range of sensor detection should preferably be in the1,000-5000 psi range or higher. The sensor output, and the output from aforce sensor associated with fluid-source assembly 174, are fed to alogic circuit in the controller whose components and operation will nowbe described with reference to FIGS. 9 and 10. The operation isdescribed for the case where the hydraulic fluid supplied from thecontroller to the stapler is water or other suitable liquid. In thediagram in FIG. 9, the rounded rectangles are user buttons, therectangles with heavy grey borders and enlarged font type are displaybuttons, and other boxes show controller operations. The buttons anddisplay windows are displayed on the front of the controller panel.

To begin an operation, the user loads the syringes, mounts the loadedsyringes in the controller, connects the syringe to the stapler device,and purges air from the system, e.g., by opening bleed screw 77 on thestapler, as described above and indicated at 200 in the figure. Thevacuum source, e.g., pump, is also connected to the stapler devicethrough the controller. When the “setup” button 200 on the controller ispressed, the controller sequentially activates the stepper motors ofboth fluid sources, forcing any air in a syringe or feeder line out ofthe system. In addition, the user may verify proper setup with apressure check of both compression and stapling systems using the TestFire functionality 202.

After guiding the stapler to a selected position within the patient'sstomach, the user will initiate a tissue-acquisition step by pressingthe “Prep” button 204. This will activate the first fluid source,supplying fluid to the first stapler piston to move the staple and anvilmembers in the stapler from their open position to theirtissue-acquisition position, indicated as the “Elbows position” at 206in FIG. 9. This position is achieved by supplying a selected volume ofliquid, as measured by the syringe “on” time or motor step count, fromthe first fluid source to the first stapler piston. The controller willnow either indicate at 206 that the stapler is ready for tissueacquisition, or invite the user to make a manual elbows adjustment byincreasing or decreasing fluid pressure, as indicated by the adjustmentloop 206 in FIG. 9. This loop allows the user to increase (208) ordecrease (210) the amount of volume supplied to the first piston duringthe “elbow position” operation, for accurate placement of the stapler atits tissue-acquisition position.

When the desired tissue-acquisition position is reached, the controllercan be set to either automatically activate the vacuum switch or waitfor the user to press the vacuum button 212. In either event, a vacuumis applied to the stapler tissue chamber, drawing a tissue fold into thechamber. After tissue acquisition, the controller, either automaticallyor by user command by pressing “Compress” button 214, will then supplyfluid to the first source to move the staple and anvil members to theircompress position, where tissue is compressed in the fixed gap betweenthe two staple members. Also after the staple and anvil members havemoved to their compress position, the vacuum switch is closed,preventing unwanted suction on the tissue surrounding the fold. Theforce on the first syringe is now checked to ensure that a preselectedpressure is being applied to the stapler, to hold the two staplermembers at or above a preselected pressure that will ensure a successfulstapling operation. This pressure, which is measured by the load cell inthe first fluid source, is confirmed at display 216.

Once this pressure is confirmed, the controller, either automatically orby the user pressing the “Staple” button 218, will activate the secondfluid source to initiate tissue stapling. The pressure measured by thesecond source is then used to determine if there has been a successfulstaple “crush” at 220. Here it will be appreciated that having apreselected pressure in the first fluid source ensures that the stapleand anvil members will be held together with a force that is sufficientto resist the stapling force that acts to push the two members apart,ensuring the staple will be properly bent or “crushed” during a staplingoperation. The crush event is reflected in the fluid pressure measuredat the second source during a stapling operation and a “crush” isdetected at 204. If a successful crush is not detected, the controllerwill proceed through a loop 222 that will allow the user to increase thesecond source pressure, to achieve crush. When a successful crush isobtained, the controller will release pressure to the second fluidsource, by reversing the direction of the fluid-source stepper motor, toreturn the stapler to a ready position.

After second fluid source has released pressure, the controller caneither automatically or on user command proceed to “release,” at 224,and reduce the pressure supplied to the first fluid source, by reversingthe direction of the fluid-source stepper motor, causing the staple andanvil members to move away from the compress position, and allow tissuerelease from the stapler. The controller will enable the user tomanually control elbow adjustment by increasing or decreasing fluidpressure, as indicated by the adjustment options 208 and 210, which willenable the user to facilitate tissue release, Finally, the controllercan either automatically, or on user command fully release pressure onthe first syringe to “return to home position,” at 226, which fullyretracts the staple and anvil members.

To summarize operation the steps above, the user will:

Insert the stapler into the patient, after purging the system of gas,and position the stapler head at the desired location and set the tissueacquisition position with the PREP button.

Acquire tissue with the VACUUM button.

Compress tissue by pressing COMPRESS, after which vacuum turns offautomatically at full compression pressure.

Press STAPLE to actuate the staple firing sequence.

Press RELEASE, to withdraw the stapler from the patient and perform thereloading procedure.

FIG. 10 describes the basic logic circuitry of the controller in termsof the sensor readings and user input during a stapling operation. Asseen, the controller has three sensors that it responds to: first andsecond pressure (force) sensors 230, 232, respectively, and a volumesensor 234 based on stepper motor rotation count 236 in the first fluidsource. The first controller operation, at 238, confirms that the fluidlines and syringe are gas-free, using pressure measurements from bothfluid sources, after the fluid lines have been bled at 240 to releaseentrapped gas. Alternatively, the controller could confirm gas-freelines by activating the fluid sources for a time sufficient to purge anygas in the lines, before connecting the lines to the stapler asdescribed.

After placing the stapler in the patient at a desired location, at 242,the user will press Prep at 244 to signal the controller activateSyringe-1 to move staple and anvil members to their tissue-acquisitioncondition 246. When the stapler reaches this condition, based onSyringe-1 volume determination from volume sensor 234, the controllerwill either switch on vacuum, for tissue acquisition (250), or signalthe user that the staple is ready for tissue acquisition, by switchingon vacuum (248).

After a suitable period for tissue acquisition, e.g., 2-5 seconds, thecontroller will either automatically activate the first fluid source tomove the stapler members to their compress position (252) or signal thatuser that the system is now ready for the tissue compress stage, at 254.During the period when the staple and anvil members are moved from theirtissue-acquisition to tissue-compress positions, the controller operatesto switch off vacuum, causing a gradual loss in vacuum in the tissuechamber, as the tissue is being captured between the two staple members.

At this stage, the controller will check the pressure on Syringe-1 at256 to confirm that the staple member is held at the compress conditionwith enough force to adequately resist the tendency of the staple andanvil members to move away from one another during stapling. With thisforce confirm, the controller will either automatically activateSyringe-2 for stapling, at 258, or signal the user that the system isready for staple activation at 260.

During the stapling operation, the controller monitors pressure fromSyringe-2 to determine if the pressure applied to the syringe issufficient to produce a staple “crush,” at 262. If insufficient pressureis detected, the controller will increase the pressure in both Syringe-1and Syringe-2 until a sufficient crush pressure is achieved. Ifsufficient crush pressure is measured, the controller will eitherautomatically operate the fluid sources to allow release of stapledtissue (264) and return to the stapler home position (266), or signalthe user that it is safe to perform these functions, at 268.

In addition to these basic function, the controller has built into itscircuitry a number of features that prevent unwanted actions, either bythe user or the stapler, including the features that:

1. The Vacuum button must be held down to activate vacuum except whentissue acquisition is imminent (PREP position). This prevents thestapler from acquiring tissue inadvertently, especially while enteringthe stomach.

2. The vacuum switches off once compression pressure reaches a setvalue. This prevents injuring the stomach tissue through prolongedsuction.

3. The vacuum cannot be switched on with a momentary press of buttonexcept during tissue acquisition. This prevents the vacuum fromremaining on without user input except when tissue acquisition isimminent (PREP position).

4. The stapling pressure is always released before compression pressure.This prevents overload condition on certain mechanical connectionswithin stapler head.

5. Pressure ramp is monitored and compared to expected values. Thisprevents use of system if setup, specifically de-airing of syringes, hasnot been performed properly.

6. Certain buttons are locked out in certain states. Inappropriateactions are prevented by deactivation of buttons.

7. Expanding stapler head can only occur with 3 second buttonactivation. This prevents inadvertent stapler head expansion.

8. Tissue release is managed by staged collapse of stapler head back toinsertion profile, and manual pressure control is active to facilitatetissue release. This reduces likelihood of tissue captured in staplerhead mechanism during release of tissue.

9. User override of pressure is limited to 20% above that required forproper stapler function. This prevents user from overriding system tothe point of stapler or HydroForce damage.

10. The position of the syringe plunger is monitored. This preventsactuation of stapler if fluid level is insufficient, or leak rate isoutside of certain limits.

11. Pause is available at all times except when stapling is occurring.

12. Door and syringe interlocks prevent actuation if door is open orsyringe is absent.

While the invention has been described with respect to certainembodiments, and operations, it will be appreciated that variousmodifications may be made without departing from the spirit of theinvention.

What is claimed is:
 1. An endoscopic stapler, comprising: a staplemember including a staple holder, the staple holder including one ormore staples; an anvil member spaced apart from the staple member,wherein the staple member and the anvil member are configured torelatively move towards one another; a controller fluidly coupled to thestaple member through a plurality of conduits, wherein the controller isconfigured to (a) direct a pressurized fluid to the staple memberthrough a first conduit of the plurality of conduits to relatively movethe staple member and the anvil member towards one another, and (b)direct the pressurized fluid through a second conduit of the pluralityof conduits to eject one or more staples from the staple holder; a firstswitch, the activation of which initiates a supply of pressurized fluidthrough the first conduit; a first sensor adapted to detect a pressureapplied to the staple member in response to pressurized fluid in thefirst conduit; and a second switch, the activation of which initiates asupply of pressurized fluid through the second conduit, wherein thesecond switch is automatically activated when the first sensor indicatesthat a preselected pressure has been reached.
 2. The endoscopic staplerof claim 1, wherein the staple member includes a hydraulic chamberfluidly coupled to the controller through the plurality of conduits, thehydraulic chamber including a first piston and a second piston therein,wherein the first piston is configured to relatively move the staplemember and the anvil member towards one another, and the second pistonis configured to eject one or more staples from the staple holder. 3.The endoscopic stapler of claim 2, wherein the second piston ispositioned within the first piston.
 4. The endoscopic stapler of claim2, wherein directing pressurized fluid through the first conduit jointlymoves the first piston and the second piston from a first position to asecond position, and directing pressurized fluid through the secondconduit moves the second piston relative to the first piston from thesecond position to a third position away from the first position.
 5. Theendoscopic stapler of claim 1, wherein the first conduit is coupled to afirst fluid source containing a predetermined quantity of fluid, and thesecond conduit is coupled to a second fluid source containing apredetermined quantity of fluid.
 6. The endoscopic stapler of claim 1,wherein relative movement of the staple member and the anvil membertowards one another includes at least one of the staple member or anvilmember moving reciprocally toward the other of the staple member oranvil member along an axis.
 7. An endoscopic stapler, comprising: astaple member including: a hydraulic chamber with a first piston and asecond piston positioned therein; and a staple holder including one ormore staples positioned therein; an anvil member spaced apart from thestaple member, wherein the staple member and the anvil member areconfigured to relatively move towards one another; and a controllerhaving a first fluid source fluidly coupled to the hydraulic chamberthrough a first conduit, a second fluid source fluidly coupled to thehydraulic chamber through a second conduit, a first plunger, and asecond plunger, the controller being configured to (a) advance a firstpusher unit fixed to the first plunger to i) move the first plungerrelative to the first fluid source to direct pressurized fluid throughthe first conduit, and ii) jointly move the first piston and the secondpiston from a first position to a second position to relatively move thestaple member and the anvil member towards one another, and (b) advancea second pusher unit fixed to the second plunger to i) move the secondplunger relative to the second fluid source to direct pressurized fluidthrough the second conduit, and ii) move the second piston relative tothe first piston from the second position to a third position to ejectone or more staples from the staple holder.
 8. The endoscopic stapler ofclaim 7, further including: a first switch, the activation of whichinitiates a supply of the pressurized fluid through the first conduit; afirst sensor configured to detect a pressure applied to the staplemember in response to pressurized fluid in the first conduit; and asecond switch, the activation of which initiates a supply of thepressurized fluid through the second conduit, wherein the second switchis automatically activated when the first sensor indicates that apreselected pressure has been reached.
 9. The endoscopic stapler ofclaim 7, wherein relative movement of the staple member and the anvilmember towards one another includes (i) the staple member moving towardsthe anvil member, and (ii) the anvil member moving towards the staplemember.
 10. A method of operating an endoscopic stapler including (a) astaple member with one or more staples and (b) an anvil member,comprising: positioning the stapler within a patient; actuating acontroller a first time to direct a pressurized fluid to the staplemember through a first conduit to relatively move the staple member andthe anvil member towards one another; using a sensor, sensing a pressureapplied to the staple member in response to the pressurized fluid in thefirst conduit; and when a preselected pressure is sensed by the sensor,automatically actuating the controller a second time to direct apressurized fluid to the staple member through a second conduit to ejectone or more staples from the staple member.
 11. The method of claim 10,wherein relatively moving the staple member and the anvil member towardsone another includes (i) moving the staple member towards the anvilmember, and (ii) moving the anvil member towards the staple member. 12.The method of claim 10, wherein the staple member includes a hydraulicchamber with a first piston and a second piston positioned therein, andactuating the controller the first time includes jointly moving thefirst piston and the second piston from a first position to a secondposition to relatively move the staple member and the anvil membertowards one another.
 13. The method of claim 12, wherein actuating thecontroller the second time includes moving the second piston relative tothe first piston from the second position to a third position to ejectone or more staples from the staple member.
 14. The method of claim 13,further including positioning tissue between the staple member and theanvil member before the step of actuating the controller a second time.